Lightning aebestee



(No Model.) I 2 Sheets-Sheet 2.

O. 0.0HESNEY. LIGHTNING ARRESTER.

Patented Aug. 17, 1897.

mvzmom C Chaney.

mininga WITNESSES ATTORNEY UNITED STATES PATENT OFFICE.

CUMMINGS O. CI'IESNEY, OF PITTSFIELD, MASSACHUSETTS, ASSIGNOR OFONE-HALF TO JOHN F. KELLY, OF SAME PLACE.

LIGHTNING-ARRESTER.

SPECIFICATION forming part of Letters Patent No. 588,320, datedAugust17, 1897.

Application filed May 14, 1897.

To all whom it may concern:

Be it known that I, CUMMINGS O. CHEsNEY, a citizen of the UnitedStates,residing at Pittsfield, county of Berkshire, and State ofMassachusetts, have invented certain new and useful Improvements inLightning-Arresters,

of which the following is a full, clear, and exact description.

My invention relates to improvements in lightning-arresters; and itconsists in the novel construction, form, and arrangementof the partsthereof hereinafter described.

The object of my invention is to provide a simple, inexpensive, compact,and effective lightning-arrester.

My invention is illustrated by the accompanying drawings, in which-Figure I is a plan view. Fig. 2 is a front elevation. Fig. 3 isavertical section on the line no 00, Fig.2. Fig. at is a horizontalsection on the line y y, Fig. 3.

A is an insulated support.

B B are terminal binding-posts.

D is an upper cap, of insulating material, suitably secured to thesupport A and pr0- vided with perforations D.

E is a lower cap, of insulating material, suitably secured to thesupport A and provided with perforations E. In the space between thecaps D and E is held a series or nest of concentric cylinders F,preferably formed of any metal. having a fairly high melting-point, evencommon yellow brass answering very well. The upper ends of the cylindersF flare outwardly, forming a series of concentric cones, which bypreference successively increase in the angle of the apex. Vhile theparts F are not, strictly speaking, cylinders, they will, for thepurposes of this description, be termed cylinders. To the innermostcylinder F the line-circuit may be electrically connected through theterminal B, or instead of connecting the said line-circuit to theinnermost cylinder a separate post G may be provided, the latterconstruction being shown-in the drawings. The outer cylinder F isgrounded through the terminal B. WVhile it is manifest that theseconnections may be reversed, it is preferred that the linecircuit shouldlead to the center of the nest, as the surrounding parts serve toprotect the Serial No. 686,536. (No model.)

same. The post G, while performing the function of a conductor, may alsoserve as a binding means to draw the insulating-caps D E into tightcontact with the parts F. The insulating-pieces D E, besides serving tohold the parts F in proper relative position, also prevent arcing acrossthe ends, which would tend to short-circuit the arrester. Theinsulating-pieces D E are, by preference, provided with suitable groovesor ridges to receive the ends of said cylinders. Each nest of concentricparts is a complete and operative arrcsier. In the drawings,h0wever,twonests are shown, one for each branch of the circuit to be protected,and, as shown, each nest has a common ground through the connection G.

In operation the lightning starts a series of arcs across the gaps inthe narrower end of the arrester and the excessive current passes to theground through the terminal B. At the same time a current of air isestablished through the perforations E D and between the parts F, thesaid current tending to blow the arcs upward into the spaces between theflaring ends of the cylinders. As these arcs continue to travel upwardthe distances between the parts F increase and the surface of metalexposed to heating is also increased. Thus the maintenance of the arcsbecomes more and more difficult. This continues until one of the arcs isbroken which of course ruptures the circuit.

.Among the advantages of the construction herein described are thefollowing:

First. The dividing of the excessive current into a series of small arcsrenders it more difficult to maintain the same than in the case of asingle are equal to the sum of the lengths of the small ones. Hence assoon as the lightning has been discharged the arcs are readily blown outor interrupted and the ground-circuit broken.

Second. There being no points of metal to localize the arcs, the sameare very unstable and are readily interrupted.

Third. Blowing the arcs through grad uallyincreasing spaces and towardthe upper end of the arrester stretches said arcs until they may bereadily interrupted.

Fourth. As the surface of metal exposed to heating increases toward theupper or flar- IOO ing end of the arrester, the temperature tends to belower at that end, and hence makes it more difficult to maintain theare.

In the drawings the preferable form of the parts F is shown, in whichthe lower ends of the said parts aresubstantially parallel-sided, whilethe upper ends only are made to flare outwardly.

\Vhat I claim is 1. In a lightning-arrester, a series of concentriccylinders having flaring sides, said cylinders being spaced apartthroughout their length, suitable insulated supporting means andcircuit-terminals, therefor.

2. In a lightning-arrester, a series of con centric cylinders hayingflaring sides, insulated retaining-pieces at opposite ends of saidcylinders, said pieces having openings therein, circuit-terminals forthe inside and outside cylinders.

3. In a lightning-arrester, a series of concentric cylinders havingflaring sides, which successively increase in the angle of the apex,insulated supporting and retaining pieces at opposite ends of saidcylinders, said pieces being perforated, circuit-terminals for theinside and outside cylinders.

21:. In a lightning-arrcster, a series of concentric parts, spaced apartthroughout, said parts being substantially parallel toward their lowerends,and Ilarin g outwardly toward their upper ends, circuit-terminalstherefor.

5. In a lightning-arrester, a series of concentric parts nestedtogether, but separated from each other throughout their entire length,the lower ends of said parts being parallel, while the upper ends flareoutwardly, the flaring ends increasing successively in the angle of theapex, and circuitterininals therefor.

6. In a lightning-arrester, a nest of concentric cylinders havingfiaring sides, said parts being separated from each other, alineterminal and a ground-terminal, the latter being connected to theouter cylinder, substantially as, and for the purpose specified.

CUMMINGS C. GI'IESNEY.

\Vitnesses:

J OHN F. KELLY, HARRY G. GoEwnY.

